This study explored the effectiveness of gender-based violence (GBV) interventions on young people living with or affected by HIV in low- and middle-income countries (LMICs).Systematic review and meta-analysis.We pre-registered a protocol, then searched 13 databases and grey literature. We screened randomized and quasi-experimental studies (n = 2199) of young people (aged 10-24) living with or affected by HIV in LMICs. Outcomes were GBV and/or GBV-related attitudes. We appraised the data for risk of bias and quality of evidence. Narrative syntheses and multilevel random effects meta-analyses were conducted.We included 18 studies evaluating 21 interventions. Intervention arms were categorized as: sexual health and social empowerment (SHSE; n = 7); SHSE combined with economic strengthening (n = 4); self-defence (n = 3); safer schools (n = 2); economic strengthening only (n = 2); GBV sensitization (n = 2) and safer schools and parenting (n = 1). Risk of bias was moderate/high and quality of evidence low. Narrative syntheses indicated promising effects on GBV exposure, but no or mixed effects on GBV perpetration and attitudes for self-defence and GBV sensitization interventions. Safer school interventions showed no effects. For SHSE interventions and SHSE combined with economic strengthening, meta-analyses showed a small reduction in GBV exposure but not perpetration. Economic-only interventions had no overall effect.SHSE, SHSE plus and self-defence and gender sensitization interventions may be effective for GBV exposure and GBV-related attitudes but not for GBV perpetration. However, the quality of evidence is poor. Future intervention research must include both boys and girls, adolescents living with HIV and key populations.